On July 12, 2007, Hupe, Eike; Zagar, Cyrill; Witschel, Matthias; Kuehn, Toralf; Moberg, William Karl; Parra Rapado, Liliana; Stelzer, Frank; Vescovi, Andrea; Reinhard, Robert; Sievernich, Bernd; Grossmann, Klaus; Ehrhardt, Thomas published a patent.SDS of cas: 50743-01-6 The title of the patent was Preparation of piperazine-2,5-diones as herbicides. And the patent contained the following:
Title compounds [I; R1, R2 = cyano, alkyl, cycloalkyl, (cyclo)alkenyl, (cyclo)alkynyl, Ph, phenylalkyl, heterocyclyl, etc.; R3 = H, halo, cyano, alkyl, cycloalkyl, alkenyl, alkynyl, cycloalkynyl, Ph, phenylalkyl, etc.; R4-R6 = H, OH, (substituted) alkyl, alkoxy; A1, A2 = (hetero)aryl; R9 = halo, cyano, NO2, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkadienyl, alkynyl, etc.; R10-R14 = H, halo, cyano, NO2, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkadienyl, alkynyl, etc.], were prepared Thus, methanesulfonic acid [(5-benzyl-1,4-dimethyl-3,6-dioxopiperazin-2-yl)-(2-nitrophenyl)methyl] ester (preparation given) was dropwise treated with DBU in THF at 0掳 followed by 4 h stirring at 0掳 to give 76% 3-benzyl-1,4-dimethyl-6-(2-nitrobenzylidene)piperazine-2,5-dione. I at 0.5-3 kg/ha were said to show very strong pre- and postemergent herbicidal activity. The experimental process involved the reaction of 5-Bromo-1H-imidazole-4-carbaldehyde(cas: 50743-01-6).SDS of cas: 50743-01-6
The Article related to piperazinedione preparation herbicide, Heterocyclic Compounds (More Than One Hetero Atom): Pyrazines and Quinoxalines (Including Piperazines) and other aspects.SDS of cas: 50743-01-6
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem